Proving and verifying an ordered sequence of events

Abstract

A computer implemented method of providing proof of an ordered sequence of events, the method performed on a computing device and comprising: receiving a transaction; creating a further transaction to be sent to a further computing device; obtaining proof data associated with the further transaction that provides proof to the further computing device that the further transaction is linked to an initial transaction in a transaction chain comprising the transaction, wherein the initial transaction relates to an initial event in the ordered sequence of events, and the proof data comprises: (i) a proof; (ii) an identifier of the transaction; and (iii) a unique identifier of the initial transaction; and sending the further transaction and the proof data to the further computing device.

1 . A computer implemented method of providing proof of an ordered sequence of events, the method performed on a computing device and comprising:
 receiving a transaction;   creating a further transaction to be sent to a further computing device;   obtaining proof data associated with the further transaction that provides proof to the further computing device that the further transaction is linked to an initial transaction in a transaction chain comprising the transaction, wherein the initial transaction relates to an initial event in the ordered sequence of events, and the proof data comprises: (i) a proof; (ii) an identifier of the transaction; and (iii) a unique identifier of the initial transaction; and   sending the further transaction and the proof data to the further computing device.   
     
     
         2 . The method of  claim 1 , wherein the transaction is the initial transaction, and obtaining the proof data comprises: setting the proof to a predetermined proof value, and setting the identifier of the transaction to a predetermined initial value. 
     
     
         3 . The method of  claim 1 , wherein the transaction is not the initial transaction of the transaction chain, the method comprises verifying that the transaction complies with at least one predetermined condition. 
     
     
         4 . The method of  claim 3 , wherein the at least one predetermined condition specifies that the transaction spends a transaction output of a previous transaction in the transaction chain. 
     
     
         5 . The method of  claim 3 , wherein the at least one predetermined condition specifies that the transaction comprises an index of a transaction output of the transaction. 
     
     
         6 . The method of  claim 3 , wherein obtaining the proof data comprises generating the proof using the transaction and a proving key; and computing the identifier of the transaction. 
     
     
         7 . The method of  claim 1 , wherein the method comprises including the proof data in the further transaction. 
     
     
         8 . The method of  claim 7 , wherein the method comprises including the proof data in a spendable output of the further transaction. 
     
     
         9 . The method of  claim 7 , wherein the method comprises including the proof data in an unspendable output of the further transaction. 
     
     
         10 . The method of  claim 1 , wherein the proof data is not included in the further transaction and the method comprises separately sending the further transaction and the proof data to the further computing device. 
     
     
         11 . The method of  claim 1 , wherein the transaction represents a transfer of ownership of a digital asset to a user associated with the computing device, and the further transaction represents a transfer of ownership of the digital asset to a further user associated with the further computing device. 
     
     
         12 . (canceled) 
     
     
         13 . The method of  claim 1 , wherein the transaction is associated with event data, wherein the event data relates to an event in the ordered sequence of events; and wherein the further transaction is associated with further event data relating to a later event in the ordered sequence of events. 
     
     
         14 . The method of  claim 13 , wherein the event data comprises a data record associated with a physical or digital object, and the further event data comprises a further data record associated with the physical or digital object. 
     
     
         15 . The method of  claim 13 , wherein the event data comprises a data record associated with a user, and the further event data comprises a further data record associated with the user. 
     
     
         16 . The method of  claim 13 , wherein the transaction comprises a representation of the event data, and the further transaction comprises a representation of the further event data. 
     
     
         17 . The method of  claim 13 , wherein the event data is stored on a remote device in association with the identifier of the transaction, and the method comprising storing the further event data on the remote device in association with an identifier of the further transaction. 
     
     
         18 . The method of  claim 1 , wherein the transaction and the further transaction are blockchain transactions. 
     
     
         19 . (canceled) 
     
     
         20 . A non-transitory computer readable storage medium comprising computer readable instructions that, when executed by a computing device, cause the computing device to perform a method of providing proof of an ordered sequence of events, the method performed on a computing device and comprising:
 receiving a transaction;   creating a further transaction to be sent to a further computing device;   obtaining proof data associated with the further transaction that provides proof to the further computing device that the further transaction is linked to an initial transaction in a transaction chain comprising the transaction, wherein the initial transaction relates to an initial event in the ordered sequence of events, and the proof data comprises: (i) a proof; (ii) an identifier of the transaction; and (iii) a unique identifier of the initial transaction; and   sending the further transaction and the proof data to the further computing device.   
     
     
         21 . (canceled) 
     
     
         22 . A computer implemented method of verifying an ordered sequence of events, the method performed on a computing device and comprising:
 receiving a transaction from a further computing device;   receiving, from the further computing device, proof data associated with the transaction, the proof data comprising: (i) a proof; (ii) an identifier of a previous transaction in the transaction chain; and (iii) a unique identifier of an initial transaction of the transaction chain, wherein the initial transaction relates to an initial event in the ordered sequence of events; and   verifying that the transaction is linked to the initial transaction in the transaction chain using the proof, the identifier of a previous transaction in the transaction chain, the unique identifier of the initial transaction, and a verification key.   
     
     
         23 - 34 . (canceled) 
     
     
         35 . A non-transitory computer readable storage medium comprising computer readable instructions that, when executed by a computing device, cause the computing device to perform a method of verifying an ordered sequence of events, the method performed on a computing device and comprising:
 receiving a transaction from a further computing device;   receiving, from the further computing device, proof data associated with the transaction, the proof data comprising: (i) a proof; (ii) an identifier of a previous transaction in the transaction chain; and (iii) a unique identifier of an initial transaction of the transaction chain, wherein the initial transaction relates to an initial event in the ordered sequence of events; and   verifying that the transaction is linked to the initial transaction in the transaction chain using the proof, the identifier of a previous transaction in the transaction chain, the unique identifier of the initial transaction, and a verification key.   
     
     
         36 . (canceled)